As shown in FIG. 1, a steering column device 101 of WO2012/000593A1 includes an outer column 103 fixed to the side of a vehicle body. Into this outer column 103, a cylinder-shaped inner column 104 is inserted so as to be movable in the longitudinal direction of a vehicle. Fastening mechanism 105 is provided to fasten this inner column 104 to the outer column 103. Impact absorbing mechanism 106 is provided to absorb impact energy when an impact accident causes a secondary collision where a passenger collides with a steering wheel.
The fastening mechanism 105 includes a pair of clamp parts 132 which stand from the outer column 103 so as to interpose the inner column 104 therebetween. An operating shaft 151 penetrates through the pair of clamp parts 132. The inner plate 104 is provided with a lock plate 161 extending along the direction of a cylinder axis. The lock plate 161 is in the form of a ladder where multiple lock holes 161 are formed in a belt-shaped member successively in the longitudinal direction. A lock claw 162 is arranged on the operating shaft 151. By rotationally operating the operating shaft 105 about its axis, the lock claw 162 is detachably engaged with the lock holes 161a. The lock plate 161 is retained in an arbitrary position since the lock claw 162 is engaged with a bar 163 dividing the adjoining lock holes 161a. 
When the inner column 104 moves forward due to a collision with a passenger, the impact absorbing mechanism 106 absorbs impact energy since an energy absorbing member arranged between the inner column 104 and the lock plate 161 retained in the arbitrary position is bent as if it were drawn.